JPS63214982A - Read in reading system in disk reproducing device - Google Patents

Abstract

PURPOSE:To shorten the memory time of required information and to shorten a time to start a reproduction by carrying out a frame calculation when the information required for reading the time code of a read in part is not obtained, jumping a track and reading a next time code. CONSTITUTION:At the time of reading the time code as an accumulating totals recorded in the read in part, when a predetermined code is not detected, the calculation of the frame is executed to jump the track, other time code is read again to read the predetermined code, thereafter, the required code of the time code is read. In such a way, only the required information is read, thereby, the memory of a small capacity may be used and the required information can be rapidly obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a disc in which, when reading a cumulative time code (hereinafter referred to as TOC) in the lead-in during disc playback, the beginning of the TOC is found. The present invention relates to a lead-in reading method in a playback device.

[Conventional technology and its problems]

On an optical disc, such as a compact disc, the first part where information is read by the pickup, that is, the lead-in part, contains the TO, which is the cumulative time code.
C is recorded continuously. This TOC records the total number of songs recorded on the disc, the playback time (hours and minutes) of the total number of songs, and the address and playback time of each song.

Normally, when reading this data, first read the total number of songs,
You need to read the playback time of all songs and the address of each song in that order.

For this reason, conventionally, when reading the TOC of the above-mentioned or -do-in part with a pickup, the read data is discarded until the entire number of songs can be read, and the time until the total number of songs can be read is wasted. However, there is a problem in that it takes time to read all the information mentioned above, and it takes a long time to start playback.

[Purpose of the invention]

The present invention is an attempt to solve the above-mentioned problems.When reading the TOC in the lead-in part at the start of disc playback, only the necessary information out of a large amount of information can be read, thereby requiring only a small memory capacity. and to provide a lead-in reading method for a disc playback device, which, when reading the necessary information, if the necessary information cannot be obtained in the first reading, track jump is performed to quickly obtain the necessary information. With the goal.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention has the following advantages: T in the lead-in portion at the start of disc playback.

When reading C, only the necessary information is read out of a large amount of information, and if the necessary information is not obtained in the first reading when reading the necessary information, track jump is performed to immediately obtain the necessary information. This is to obtain the following.

[Embodiment of the Invention] Next, a case where an embodiment of the present invention is applied to a disc playback device that selects and plays one disc from a magazine containing a large number of discs will be explained with reference to FIG. .

In FIG. 1, l is a magazine that stores N (N is a natural number of 2 or more) disks arranged in order at a predetermined pitch. The magazine 1 is provided with N trays for carrying disks in a housing that protrudes from the magazine body. The magazine 1 is detachably attached to a predetermined attachment portion. One of the N disks D I''' D s stored on N trays each serving as a plurality of disk storage positions provided in this magazine 1 is rotated by the spindle motor 3 by the disk ejecting and conveying mechanism 2. The disk is conveyed onto the disk supporting surface of the turntable 4 fixed to the shaft and is clamped.The disk ejecting and conveying mechanism 2 has a protrusion that protrudes the tray of the magazine 1 and moves the disk onto the disk supporting surface of the turntable 4. a clamping mechanism that clamps the disc when the disc is moved onto the disk supporting surface of the turntable 4 by the protruding member; and a moving plate that changes the relative position of the protruding member with respect to the magazine 1 in the tray arrangement direction. , and a sensor for detecting the position of the movable plate, the operation of the clamp mechanism, etc. By moving the movable plate in the disk ejecting and conveying mechanism 2, the position of the protruding member changes, and the selection of the disk is performed. The configurations of the magazine 1 and the disk ejecting and transporting mechanism 2 are detailed in Japanese Patent Application No. 153651/1983.

Recorded information on the disk Dn, which is taken out from the magazine 1 by the disk ejecting and conveying mechanism 2 and clamped onto the disk supporting surface of the turntable 4, is read by the optical pickup 6. The pickup 6 includes a laser diode, an objective lens, a focus actuator, a tracking actuator, a photodetector, and the like.

The output of the pink-up 6 is supplied to each of a focus servo circuit 7, a tracking servo circuit 8, and a reproduction clock generation circuit 9 including an RF amplifier.

In the focus servo circuit 7, a focus error signal is generated by, for example, an astigmatism method, and a focus actuator in the pickup 6 is driven in accordance with this error signal. As a result, the laser light emitted from the laser diode and passed through the objective lens is focused on the recording surface of the disk Dn, forming an information detection light spot. Further, in the tracking servo circuit 8, a tracking error signal is generated by, for example, a push-pull method, and this error signal is sent to the trunking actuator in the pink-up 6 and the carriage servo circuit 10. The output of the carriage servo circuit 10 is supplied to a motor Ma that drives a carriage (not shown) carrying the pickup 6, and the pickup 6 is sent in the radial direction of the disk Dn.

A reproduced clock signal for demodulation is generated in the reproduced clock generation circuit 9 and supplied to the spindle servo circuit ll. In the spindle servo circuit 11, a drive signal according to the phase difference between the reproduced clock and the reference clock from the clock generation circuit 12 is generated to drive the spindle motor 3, and control the track linear velocity of the disk Dn to be constant. be done. Further, the output of the RF amplifier in the reproduced clock generation circuit 9 is supplied together with the reproduced clock to an EFM demodulation circuit 13 including a frame synchronization circuit. The demodulated output of the EFM demodulation circuit 13 is processed by a data processing circuit 14 that performs deinterleaving, error detection, correction, correction, etc. of the demodulated data signal.

Thereafter, the demodulated output is temporarily stored in a data memory 15, read out using a clock signal from a clock generation circuit 12, and converted into an analog signal by a D/A (digital/analog) converter 16. This analog signal is output as left and right audio signals via an LPF (low pass filter) 17 and an amplifier 18. Furthermore, amplifier 18
is configured to receive control data and change its frequency characteristics in accordance with the control data.

On the other hand, the control (No. 8) in the data from the EFM demodulation circuit 13 is supplied to the system controller 20, and various information such as during the song, between songs, song number, playing time, disc model number, etc. is read. The system controller 20 is formed of one or more microcomputers including a processor, ROM (read-only memory), RAM (random access memory), an interface circuit, a timer, etc. , the processor operates according to a program stored in the ROM in advance and based on the flowchart shown in FIG. The random number generation circuit 23, which processes and supplies various commands and data to the carriage servo circuit 10, spindle servo circuit 11, amplifier 18, display 22, and drive circuits 24 and 25, generates coefficient values in extremely short cycles, for example. The drive circuit 24.2 is configured to latch and output the output of the m-ary (m is a natural number) counter that changes sequentially in response to a data output command.
Reference numeral 5 is configured to supply a driving current according to a command to motors Mb and Mc that respectively drive the moving plate and the protruding member in the disk ejecting and transporting mechanism 2.

Note that 26 is a RAM that stores information from the system controller 20.

S, -S are various detection switches arranged near the magazine 1 mounted in a predetermined mounting part, Sl is a magazine detection switch that sends out an output when the magazine 1 is mounted in a predetermined mounting part, S8 1 is a disk detection switch that detects the presence or absence of a disk in the protruded tray, S is a tray detection switch that detects whether or not a tray is stored in the magazine 1, and S4 is a magazine 1 that moves up and down with respect to the turntable 4. This is a magazine position detection switch that detects the position of the magazine.

Next, the operation of the processor in the system controller 20 will be explained with reference to the flowchart of FIG.

First, when the power is turned on, the processor monitors whether or not the magazine l has been inserted into the predetermined mounting section.Step a)
, when magazine 1 is attached to a predetermined attachment part and magazine detection switch Sl detects the cent of magazine 1 and sends the detection signal to the processor, the processor
determines that is set and proceeds to the next step, and
If it is not attached, the operation will stop.

In the next step, magazine 1 is moved up and down to set magazine 1 to a position where the top or bottom tray can be pulled out (step b), and the magazine position detection switch S sends a position signal of magazine 1. is sent to the processor, and the processor proceeds to the next step.

In the next step, it is detected whether or not there is a disk in the tray to be pulled out.Step C): When the disk detection switch S detects a disk, the next step is proceeded to.
In the next step, the processor monitors whether the regeneration switch is turned on or not (step d), and if it is not detected that the regeneration switch is turned on, the processor waits for the operation of the regeneration switch, and the regeneration switch is turned on. When turned on, the processor outputs a signal for loading a disc to the playback device.

Therefore, the playback device loads the disc (step e), rotates the disc, and jumps the pickup to the lead-in portion of the disc (step f).

At this time, the processor monitors whether or not the pick amplifier has been lead-in (step g), and if it has not been lead-in, returns to the previous step f, and when lead-in is confirmed, proceeds to the next step.

In the next step, the TOC is read (step h), and it is monitored whether the result of reading the processor TOC is point AO (step i). This point A
O is information representing the total number of songs in TOCO including a large amount of information, and it is monitored whether this information has been read. If the read result is point AO, then read the necessary information of ToC (step n), that is, the total number of songs, and the playback time (hours and minutes) of all songs.
Only the data is read and recorded in memory. This is done by dividing the total number of songs by the total playback time to determine which part of the disc the selected song corresponds to based on the total number of songs and total playback time when the operator selects the desired song. Since it is possible to do so, the address and playback time of each song can be changed as before.
This is because there is no need to read from the OC and store it in memory.

In this embodiment, since the amount of information to be stored in the memory is small, a small memory capacity can be used.

On the other hand, in reading the TOC, if the point AO is not read, the processor calculates the position of the point AO of the next TOC from the read information in step j), and then picks up the frame. (step k), read the TOC at the track jump position again (step l), and monitor whether the read TOC information corresponds to point AO (step m).
If AO is read, proceed to step n, and if point) AO is not read, return to step j of frame calculation and repeat the above operation again. If only 1 is read, the processor operation ends.

〔Effect of the invention〕

As described above, in the present invention, when reading the TOC of the lead-in part at the start of disc playback, if the necessary information is not obtained, frame calculation is performed, track jump is performed, and the next TOC is read. As a result, it is possible to shorten the time required to store only the necessary information by one hour, and the time required for starting reproduction can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a disc playback device used in the present invention, and FIG. 2 is a flowchart according to the present invention. 1...Magazine, 2...Disc ejection transport mechanism, 2
0...System controller, Sl...Magazine detection switch, St...Disk detection switch, S...
...Tray storage detection switch, S4...Magazine position detection switch.

Claims (1)

[Claims] When playing a disc set in a disc playback device, if a predetermined code is not detected when reading the cumulative time code (TOC) recorded in the lead-in part, frame calculation is performed. 1. A lead-in reading method for a disc playback device, characterized in that after the previous TOC is read and the track is jumped, another TOC is read and the predetermined code is read, a necessary code of the TOC is read.